ABSTRACT
The visual transduction process in rod photoreceptor cells for scotopic vision begins with absorption of a photon by a rhodopsin molecule, which is a seven-transmembrane
α
-helical protein having 11-
cis
- retinal as a chromophore. Light isomerizes the 11-
cis
-retinal into all-
trans
form,
resulting in conformational changes of the protein moiety to form an enzymatically active intermediate, metarhodopsin II (meta II).
